Multianalyte determination system and methods

ABSTRACT

The invention relates to embodiments of an optical system for luminescence determination, comprising two or more excitation light sources, a sensor platform and an optical component with several discrete facets for beam deflection towards the sensor platform. Further subjects of the invention are methods for luminescence determination with an optical system according to the invention and analytical systems, as well as the use of these methods for quantitative affinity sensing and for various other applications. The aim of the present invention is to provide optical and analytical measuring devices for highly sensitive detection of one or more analytes, using a multitude of measurement areas on a common carrier.

This application is a national stage entry of PCT/EP01/10012, filed Aug.30, 2001.

The invention relates to embodiments of an optical system forluminescence determination, comprising two or more excitation lightsources, a sensor platform and an optical component with severaldiscrete facets for beam deflection towards the sensor platform. Furthersubjects of the invention are methods for luminescence determinationbased thereon, with an optical system according to the invention, andanalytical systems, as well as the use of these methods for quantitativeaffinity sensing and for various other applications.

The aim of the present invention is to provide optical and analyticalmeasuring devices for highly sensitive detection of one or moreanalytes, using a multitude of measurement areas on a common carrier.

Under the attribute “biochips” various measurement devices formultianalyte detection have become known during the last years, whereina multitude of different biological or biochemical recognition elementsis immobilized on a carrier, such as a glass plate or a microscopeslide, to which recognition elements different analytes are bound in thecourse of the determination method. Most often the detection isperformed using optical methods, for example upon detection ofluminescence or more specifically fluorescence from so-calledluminescence or fluorescence labels that are applied during the assay.The discrete measurement areas with different recognition elements aregenerally called “features”.

For example in U.S. Pat. No. 5,445,934 (Affymax Technologies) arrays ofoligonucleotides with a density of more than 1000 features per squarecentimeter are described and claimed. The excitation and read-out ofsuch arrays is based on classical optical methods (epi-fluorescenceexcitation and detection, i.e. direct excitation of the features ormeasurement areas in an configuration of direct irradiation, see below).The whole array can be illuminated using an expanded excitation lightbundle, which, however, results in relatively low sensitivity, as thefraction of scattered light is relatively large and as scattered lightor background fluorescence light from the glass substrate (carrier) isgenerated also in those regions where no immobilized oligonucleotidesfor analyte binding are located. In order to limit the excitation anddetection to the regions of the immobilized features and to discriminatelight generation in the adjacent areas, confocal microscopic measurementconfigurations are often used, and the different features are read outsequentially by “scanners”, i.e. upon sequential excitation andluminescence detection by means of lateral translation of the excitationlight focus on the glass plate using movable mirrors, or by means oflateral translation of the glass plate with respect to the excitationlight beam. Such a scanner is, for example, described and claimed inU.S. Pat. No. 5,631,734. However, the sequential excitation anddetection of the measurement areas results in a relatively long timeneeded for the read-out of an array with a large number of features.Additionally, the sensitivity of such classical excitation and detectionconfigurations with direct illumination of the measurement areas,associated with the simultaneous illumination of a liquid volume thatmight be provided above said measurement areas, is not sufficient formany applications.

Typical values between 0.1 and 1 flurophore per μm² are reported as thedetection limits defining the sensitivity of the best current scanners.

For achieving lower detection limits, measurement arrangements have beendeveloped, wherein the determination of an analyte is based on itsinteraction with the evanescent field, which is associated with lightguiding in an optical waveguide, wherein biochemical or biologicalrecognition elements for the specific recognition and binding of theanalyte molecules are immobilized on the surface of the waveguide.

When a light wave is coupled into an optical waveguide surrounded byoptically rarer media, i.e. media of lower refractive index, the lightwave is guided by total reflection at the interfaces of the waveguidinglayer. In that arrangement, a fraction of the electromagnetic energypenetrates the media of lower refractive index. This portion is termedthe evanescent (=decaying) field. The strength of the evanescent fielddepends to a very great extent on the thickness of the waveguiding layeritself and on the ratio of the refractive indices of the waveguidinglayer and of the media surrounding it. In the case of thin waveguides,i.e. layer thicknesses that are the same as or smaller than thewavelength of the light to be guided, discrete modes of the guided lightcan be distinguished. As an advantage of such methods, the interactionwith the analyte is limited to the penetration depth of the evanescentfield into the adjacent medium, being of the order of some hundrednanometers, and interfering signals from the depth of the (bulk) mediumcan be mainly avoided. The first proposed measurement arrangements ofthis type were based on highly multi-modal, self-supporting single-layerwaveguides, such as fibers or plates of transparent plastics or glass,with thicknesses from some hundred micrometers up to severalmillimeters.

In WO 94/27137, measurement arrangements are disclosed, wherein“patches” with different recognition elements, for the determination ofdifferent analytes, are immobilized on a self-supporting opticalsubstrate waveguide (single-layer waveguide), excitation light beingin-coupled at the distal surfaces (“front face” or “distal end”coupling), wherein laterally selective immobilization is performed usingphoto-activatable cross-linkers. According to the disclosure, severalpatches can be arranged row-wise in common, parallel flow channels orsample compartments, wherein the parallel flow channels or samplecompartments extend over the whole length of the range on the waveguideused as a sensor, in order to avoid an impairment of light guiding inthe waveguide. However, there are no hints to a two-dimensionalintegration of multiple patches and sample compartments. In a similararrangement disclosed in WO 97/35203, several embodiments of anarrangement are described, wherein different recognition elements forthe determination of different analytes are immobilized in separate,parallel flow channels or sample compartments for the sample and forcalibration solutions of low and, optionally in addition, of highanalyte concentration. Again, no hint is given to a possibility oftwo-dimensional arrangements.

For an improvement of the sensitivity and simultaneously for an easiermanufacturing in mass production, planar thin-film waveguides have beenproposed. In the simplest case, a planar thin-film waveguide consists ofa three-layer system: support material (substrate), waveguiding layer,superstrate (respectively the sample to be analyzed), wherein thewaveguiding layer has the highest refractive index. Additionalintermediate layers can further improve the action of the planarwaveguide.

Several methods for the in-coupling of excitation light into a planarwaveguide are known. The methods used earliest were based on front facecoupling or prism coupling, wherein generally a liquid is introducedbetween the prism and the waveguide, in order to reduce reflections dueto air gaps. These two methods are mainly suited with respect towaveguides of relatively large layer thickness, i.e. especiallyself-supporting waveguides, and with respect to waveguides with arefractive index significantly below 2. For in-coupling of excitationlight into very thin waveguiding layers of high refractive index,however, the use of coupling gratings is a significantly more elegantmethod. Thereby the coupling of the irradiated excitation light into thewaveguiding layer, in which the grating is modulated, is effected whenthe coupling angle defined by the resonance condition for in-coupling ismet. The actual in-coupling angle for excitation light of a certainwavelength is dependent on the refractive index of the waveguiding layerand that one of the adjacent media (carrier layer or substrate and“superstrate”), on the thickness of the waveguiding layer, on thediffraction order to be in-coupled (for efficient in-coupling typicallythe first diffraction order), and on the grating period. In case of verythin waveguiding films (of about 100 nm to 200 nm thickness with arefractive index >2), for the in-coupling of transversally electricallypolarized light and of transversally magnetically polarized light eachthere is only one discrete coupling angle for in-coupling of theTE₀-mode or of the TM₀-mode, respectively. Such waveguides are calledmono-modal (single-mode). The in-coupling angle changes with theexcitation wavelength. For thin-film waveguides as they are described inmore detail further below, comprising a waveguiding layer withrefractive index of 2.2 and with about 150 nm layer thickness on a glasssubstrate (n=1.52; values for excitation light 0f 633 nm wavelength),the coupling angle changes by about 0.2° per 1 nm change of wavelength(for in-coupling angles between about +30° and −30° deviation from thedirection perpendicular to the waveguide surface).

As a matter of experience, coupling angles in the range between +30° and−30° deviation from the direction perpendicular to the waveguide surfaceare preferred for efficient in-coupling, especially also in order toavoid the excitation of so-called substrate modes, i.e. of light-guidingnot in the highly refractive waveguiding layer, but partially in thesubstrate located below, as the evanescent field to be used for analytedetection by luminescence detection is reduced in the presence of thesesubstrate modes.

Besides on the parameters already mentioned, the sharpness of theresonance condition is dependent on the depth of the coupling grating.As a tendency, the resonance angle is defined much sharper (with ahalf-width of the order of 0.01° and below) for shallow gratings (forexample with a grating depth of 5 nm-10 nm) than for deep gratings(with, for example, a grating depth of more than 25 nm). The diffractionefficiency of a grating, however, is the larger the deeper the gratingis. From this diffraction efficiency, however, a correspondingly highcoupling efficiency into the waveguiding film, with an unstructuredregion adjacent to the coupling grating, cannot be directly concluded,because not only the efficiency of in-coupling but also of immediateout-coupling does increase with increasing grating depth, theout-coupling occurring in the same direction as the reflection from thegrating. Therefore, there is an optimum grating depth for the maximumin-coupling efficiency (under the described conditions in the rangebetween 10 nm and 20 nm), which is also dependent on the geometry of theirradiated light beam (besides the dependence on the parameters alreadymentioned).

The described parameters are of high importance for the tolerances andfor the required precision for the manufacturing of the optical andmechanical components of an adequate analytical system for luminescenceexcitation and detection applied to planar thin-film waveguides.

In this application, the term “luminescence” means the spontaneousemission of photons in the range from ultraviolet to infrared, afteroptical or other than optical excitation, such as electrical or chemicalor biochemical or thermal excitation. For example, chemiluminescence,bioluminescence, electroluminescence, and especially fluorescence andphosphorescence are included under the term “luminescence”.

By means of highly refractive thin-film waveguides, based on an onlysome hundred nanometers thin waveguiding film on a transparent supportmaterial, the sensitivity could be increased considerably during thelast years. Detection limits between 0.01 and 0.001 fluorophores per μm²are achieved with such devices. In WO 95/33197, for example, a method isdescribed, wherein the excitation light is coupled into the waveguidingfilm by a relief grating as a diffractive optical element. Theluminescence that is excited in the evanescent field but isotropicallyemitted, from substances capable of luminescence that are located withinthe penetration depth of the evanescent field, is measured by adequatemeasurement arrangements, such as photodiodes, photomultipliers or CCDcameras. The portion of evanescently excited radiation, that hasback-coupled into the waveguide, can also be out-coupled by adiffractive optical element, like a grating, and be measured. Thismethod is described, for example, in WO 95/33198.

In order to perform, simultaneously or sequentially, exclusivelyluminescence-based, multiple measurements with essentially mono-modal,planar inorganic waveguides, for example in the specification WO96/35940, arrangements (arrays) have been proposed, wherein at least twodiscrete waveguiding areas are provided on one sensor platform in such away, that the excitation light guided in one waveguiding area isseparated from other waveguiding areas.

In the spirit of this invention, spatially separated measurement areas(d) shall be defined by the closed area that is occupied by biologicalor biochemical or synthetic recognition elements immobilized thereon,for recognition of an analyte in a liquid sample. These areas can haveany geometry, for example the form of dots, circles, rectangles,triangles, ellipses or lines.

The embodiments described by examples in the above referencedstate-of-the-art of optical systems for fluorescence or luminescenceexcitation using sensor platforms based on planar waveguides arerelated, without any exception, to excitation using only a singleexcitation wavelength. In general, the described systems additionallyrequire manual insertion of the sensor platform, followed by its carefuladjustment with respect to the excitation and detection optics. Inconclusion, these disclosed examples typically represent “home-made”constructions or prototypes, in the best case, which can be operated bya specialist, but not by a user with average education without profoundspecial knowledge.

Therefore, there is a need for a system for the measurement of opticalsensor platforms, that can be easily operated by a user and provides anautomated adjustment, if possible.

Especially for applications in biology, for example for expressionanalysis, typically different fluorescence labels are used, which areexcited at different wavelengths. As a response to this need, in case ofcommercially available scanning systems with excitation by directillumination the excitation light from two or even more laser lightsources can be directed onto the sample. Therefore, there is also a needfor a system for the excitation of sensor platforms based on opticalwaveguides, which allows the application of at least two excitationwavelengths without requiring adjustments by the user.

The solution of this task is rendered difficult by various boundaryconditions. For an efficient detection, i.e. collection of theisotropically emitted luminescence the application of imaging opticswith a numerical aperture as high as possible, comparable to the opticsof a microscope, is desired, leading to an only small working distancetowards the sensor platform. Simultaneously, the area of the sensorplatform shall be exploited as efficiently as possible, i.e. the unusedlocal separation between the in-coupling gratings and the measurementareas shall be kept small, as the basic price of the sensor platform isdependent on the size of the area to a large extent. A very smallseparation between the in-coupling gratings and the measurement areasleads to geometrical difficulties to direct the excitation light towardsthe sensor platform, passing aside of the collection optics, and toavoid a shadowing of the field-of-view of the collection optics bybeam-deflecting components, which may be located between the collectionoptics and the sensor platform. Finally, it has to be taken care ofavoiding direct reflections of excitation light towards the collectionoptics and of avoiding a further propagation of such reflected lighttowards the detector.

The task is rendered still more difficult because it is desired for manyapplications to work with open sample compartments or open receptionvessels, for receiving liquid exiting a sample compartment after theperformance of washing steps or after sequential reagent application.Such a technical task requires an essentially horizontal positioning ofthe sensor platform, so that the adaptation of the adjustment to achange of the coupling angle due to a different excitation wavelengthcannot be performed or can be performed to an only very limited extentby a rotation of the sensor platform with respect to the direction ofthe irradiated light.

The described tasks are solved by the invention disclosed in thefollowing. Additionally, the optical system according to the inventionis not only suited for luminescence excitation and detection onmeasurement areas on sensor platforms based on planar opticalwaveguides, but also of such platforms like glass plates, as they areused for conventional epi-illumination fluorescence excitation anddetection.

Subject of the invention is an optical system for luminescencedetermination, comprising at least two excitation light sources, asensor platform and an optical component with several discrete facetsfor deflecting a light beam, wherein the angle of divergence betweenexcitation light falling onto different facets of said optical componentis increased or reduced by at least a factor of 1.2 in the optical pathdeparting from said optical component, in comparison to the originaldivergence angle (between said light rays irradiated onto said differentfacets).

As described above, the in-coupling angle for excitation light ofdifferent wavelength can differ significantly in case of highlyrefractive thin-film waveguides as sensor platforms, with diffractivegratings for the in-coupling of the excitation light and modulated inthe high-refractive index layer. As an example, for sensor platformscomprising a 150 nm thin waveguiding layer of Ta₂O₅ (n=2.15 at 633 nm)on glass (n=1.52 at 633 nm) and about 12 nm deep gratings with a periodof 318 nm, the in-coupling angle for excitation light of 492 nm is about+18° and of 670 nm about −17° (with air as the medium above the couplinggrating).

For a compact construction of an optical system, however, it is ingeneral hardly advantageous to direct the excitation light of differentlight sources from longer distances and from a plurality of differentspatial directions onto a common target, instead of integratingdifferent excitation light sources at a common location in a module. Forexample for embodiments of the optical system according to theinvention, comprising thin-film waveguides as sensor platforms, it istherefore advantageous, if the angle of divergence between excitationlight falling onto different facets of said optical component isincreased by at least a factor of 1.2, preferably however by at least afactor of 1.5, in the optical path departing from said opticalcomponent, in comparison to the original divergence angle (between saidlight rays irradiated onto said different facets).

Said optical component with several discrete facets for beam deflectioncan be a multi-facet mirror with planar or curved facets, preferablywith planar facets.

In another, preferred embodiment of the optical system according to theinvention said optical component with several discrete facets for beamdeflection is a multi-facet prism with planar or curved facets,preferably with planar facets.

In combination with different excitation light sources of similar ordifferent wavelength a variety of different embodiments of the opticalsystem are possible. One possible embodiment consists in that the lightfrom two or more excitation light sources of similar or differentwavelength falls onto the same facet of said optical component for beamdeflection. Characteristic for another possible embodiment is, that adedicated facet of said optical component is provided for each differentexcitation wavelength, the excitation light of said excitationwavelength to be directed onto the corresponding dedicated facet.

When changing between excitation light source of different wavelengths,the extent of necessary adjustments shall be kept as small as possible,in order to minimize, on one side, the time required for theseadjustments, when the system is not available for acquisition ofmeasurement data, and to minimize, on the other side, the travel rangesof the mechanical positioning components, which travel ranges have adirect impact on system costs. Therefore, it is preferred that the beamdeflection of excitation light of different wavelength into differentpredefined directions occurs with an offset of less than 0.2 mm betweenthe centers of the deflected beams on the sensor platform.

For achieving a high sensitivity in luminescence detection methods, itis generally necessary to limit detection as close as possible to lightsignals emanating from the analytes to be detected and to excludeinterfering signals, such as ambient light, diffusively scattered orreflected excitation light from the signal acquisition. Therefore, itsis advantageous, if a multi-facet prism as an optical component for beamdeflection, as part of an analytical system according to the invention,comprises additional means for deflecting or masking reflections of theexcitation light emanating from the sensor platform. It is also possiblethat one or more reflective facets of the multi-facet prism are partlyor completely metallized.

The optical system according to the invention can comprise additionaloptical elements for the spectral selection of the excitationwavelength, such as interference filters or edge filters, and optionallyadditional optical elements for beam attenuation, such as opticalneutral density or grey filters, optionally provided as a “continuouslyvarying” filter with a continuous local gradient of the transmission,and/or further elements for beam guiding, such as glass fibers,optionally connected to micro lenses or diffractive optical elements, inthe optical path of the excitation light between the at least oneexcitation light source and the optical component with several discretefacets for beam deflection.

Characteristic for a possible embodiment of the system is that two ormore lasers with different emission wavelengths are used as excitationlight sources.

Additional optical elements comprising, for example, diffractive opticalelements and/or lenses for beam expansion and/or for generation of aparallel beam and/or diaphragms or masks for partial masking of the beamcan be located in the optical path of the excitation light between thelight sources and the sensor platform, in order to generate a desiredbeam profile on the sensor platform.

Characteristic for a preferred embodiment of the optical systemaccording to the invention is, that the sensor platform comprises amultitude of discrete measurement areas, in which biological orbiochemical or synthetic recognition elements for the determination ofone or more analytes are immobilized. Thereby, up to 100,000 measurementareas can be provided in a two-dimensional arrangement on the sensorplatform. A single measurement area can have an area of 0.001 mm²-6 mm².

The simplest method of immobilization of the biological or biochemicalor synthetic recognition elements consists in physical adsorption, forexample due to hydrophobic interaction between the recognition elementsand the base plate. However, the extent of these interactions can beaffected strongly by the composition of the medium and itsphysical-chemical properties, such as polarity and ionic strength.Especially in case of sequential addition of different reagents in amulti-step assay, the adhesion of the recognition elements on thesurface, after only adsorptive immobilization, is often insufficient. Ina preferred embodiment of the optical system according to the invention,the adhesion is improved by deposition of an adhesion-promoting layer onthe sensor platform for the immobilization of the biological orbiochemical or synthetic recognition elements. Especially in case ofbiological or biochemical recognition elements to be immobilized, theadhesion-promoting layer can also contribute to improve the“biocompatibility”, i.e. to preserve the binding capability of therecognition elements, in comparison with the binding capability of theserecognition elements in their natural biological or biochemicalenvironment, and to avoid a denaturation. It is preferred, that theadhesion-promoting layer has a thickness of less than 200 nm, preferablyof less than 20 nm. For the generation of the adhesion-promoting layer,many materials can be used. Without any restriction, it is preferred,that the adhesion-promoting layer comprises one or more chemicalcompounds from the groups comprising silanes, epoxides, functionalized,charged or polar polymers, and “self-organized passive or functionalizedmono- or double-layers”.

A further important aspect of the optical system according to theinvention is, that the biological or biochemical or syntheticrecognition elements are immobilized in discrete (laterally separated)measurement areas. These discrete measurement areas can be formed byspatially selective deposition of the biological or biochemical orsynthetic recognition elements on the sensor platform. Many methods canbe used for the deposition. It is preferred without any restriction ofgenerality, that the biological or biochemical or synthetic recognitionelements are deposited on the sensor platform by one or more methodsfrom the group of methods comprising “ink jet spotting, mechanicalspotting by means of pin, pen or capillary, “micro contact printing”,fluidically contacting the measurement areas with the biological orbiochemical or synthetic recognition elements upon their supply inparallel or crossed micro channels, upon exposure to pressuredifferences or to electric or electromagnetic potentials, andphotochemical or photolithographic immobilization methods.

As said biological or biochemical or synthetic recognition elements,components from the group comprising nucleic acids (e.g. DNA, RNA,oligonucleotides) and nucleic acid analogues (e.g. PNA), mono- orpolyclonal antibodies, peptides, enzymes, aptamers, synthetic peptidestructures, soluble membrane-bound proteins and proteins isolated from amembrane, such as receptors, their ligands, antigens for antibodies,“histidin-tag components” and their complex forming partners, cavitiesgenerated by chemical synthesis, for hosting molecular imprints. etc.,are deposited. It is also intended that whole cells, cell components,cell membranes or their fragments are deposited as biological orbiochemical or synthetic recognition elements.

In general, the immobilized recognition elements are selected in such away, that they recognize and bind the analyte to be determined with aspecificity as high as possible. Typically however, it must be expectedthat also a nonspecific adsorption of analyte molecules on the surfaceof the base plate does occur, especially if there are still empty sitesbetween the recognition elements immobilized in the measurement areas.Therefore it is preferred, that regions between the laterally separatedmeasurement areas are “passivated” for minimization of non-specificbinding of analytes or their tracer compounds, i.e., that compounds,that are “chemically neutral” towards the analyte, are deposited betweenthe laterally separated measurement areas (d), preferably for exampleout of the groups formed by albumins, especially bovine serum albumin orhuman serum albumin, casein, unspecific polyclonal or monoclonal, alienor empirically unspecific antibodies for the one or the multipleanalytes to be determined (especially for immuno assays),detergents—such as Tween 20®—fragmented natural or synthetic DNA nothybridizing with polynucleotides to be analyzed, such as extract fromherring or salmon sperm (especially for polynucleotide hybridizationassays), or also uncharged but hydrophilic polymers, such as polyethyleneglycols or dextranes.

The optical system according to the invention is typically characterizedin that the luminescence light from the measurement areas on the sensorplatform is directed onto at least one opto-electronic detector.

It is preferred that the luminescence light from the measurement areasis imaged onto a locally resolving detector, which is preferablyselected from the group formed by CCD cameras, CCD chips, photodiodearrays, avalanche diode arrays, multi-channel plates and multi-channelphotomultipliers.

There are various possibilities for the design of the detection beampath. As one possibility, the luminescence light from the measurementareas is imaged onto the at least one opto-electronic detector by meansof a system comprising one or more lenses and/or mirrors. It is alsopossible that one or more optical elements for selection of the emissionwavelength and discrimination of light of other wavelengths, such asdiffractive elements, interference filters or edge filters, are providedin the emission beam path between the sensor platform and the at leastone opto-electronic detector for recording the luminescence lightemanating from the measurement areas.

It is preferred that the emission beam path has a divergence orconvergence of less than 15° at the position of application of saidoptical element for the spectral selection. One possibility of thetechnical realization consists in that the optical elements forselection of the emission wavelength and for discrimination of light ofother wavelengths, such as interference filters or edge filters, arelocated between the two halves of a tandem objective.

There are also various possibilities for the design of the sensorplatform, as a part of the optical system according to the invention.The sensor platform can comprise an optically transparent support(supporting substrate), preferably of glass or a thermoplastic plastics,on which the biological or biochemical or synthetic recognition elementsare immobilized in the measurement areas.

Under the nomenclature “optical transparency” it is thereby understood,that the material characterized by this property is essentiallytransparent and thus essentially free of absorption at least at one ormore excitation wavelengths used for the excitation of one or moreluminescences.

It is preferred that the sensor platform comprises a planar opticalwaveguide.

It is especially preferred that the sensor platform comprises an opticalthin-film waveguide with a first optically transparent layer (a) on asecond optically transparent layer (b), and wherein the opticallytransparent layer (b) has a lower refractive index than the opticallytransparent layer (a).

It is preferred that in-coupling of excitation light into the opticallytransparent layer (a) is performed using a diffractive grating (c)modulated in the layer (a). Preferably, the diffractive gratingsmodulated in layer (a) are relief gratings. A sensor platform as a partof the optical system according to the invention can comprise a singleor also multiple discrete grating structures (c). Different gratingstructures (c) modulated in the optically transparent layer (a) of thesensor platform can have a common or also different grating periods.

Characteristic for a preferred embodiment of the sensor platform as partof the optical system according to the invention is, that gratingstructures (c) provided in the waveguiding layer (a) of the sensorplatform are arranged in a one- or two-dimensional array, with even,non-modulated regions of the waveguiding layer (a) being adjacent to thegrating structures in the direction of propagation of an excitationlight to be in-coupled into the layer (a), and wherein arrays of two ormore measurement areas are provided on these non-modulated regions,which can optionally additionally be fluidically sealed against eachother in discrete sample compartments.

In order to allow for a controlled removal of the excitation lightin-coupled into and guided in the layer (a) of the sensor platform andalso to minimize a cross-talk of light signals between adjacentmeasurement areas or between adjacent arrays of measurement areas it isadvantageous, if second grating structures (c′) for the out-coupling ofexcitation light and, where appropriate, of luminescence lightback-coupled into the waveguiding layer (a) are provided on the sensorplatform, in addition to grating structures (c) for the in-coupling ofexcitation light, in order to out-couple again the light guided in thewaveguiding layer (a), after its passing through the region themeasurement areas (in direction of propagation of the guided excitationlight following an in-coupling grating structure (c)). Thereby, gratingstructures (c) and (c′) can have similar or also different gratingperiods.

Characteristic for one possible embodiment is, that grating structures(c) and optionally (c′) are provided discretely for individual segments(arrangements in one- or two-dimensional arrays) of measurement areas.

It is preferred that grating structures (c) and optionally (c′) areprovided as continuous strips (columns) extending over the whole sensorplatform perpendicular to the direction of propagation of the excitationlight to be in-coupled.

Characteristic for a possible embodiment, especially for sequentialmeasurements, is that grating structures (c′) are also used asin-coupling gratings (c) upon sequential performance of measurements.

For certain applications, especially for achieving a very high densityof measurement areas without an optical cross-talk of luminescencesemanating from these measurement areas, it is preferred that gratingstructures (c) for the in-coupling and (c′) for the out-coupling oflight out of the waveguiding layer (a) of the sensor platform have thesame period and are modulated continuously below all measurement areasof the sensor platform.

For a given thickness of the optically transparent layer (a) thesensitivity of the arrangement according to the invention is the better,the larger the difference between the refractive index of the layer (a)and the refractive indices of the surrounding media is, i.e., the largerthe refractive index of the layer (a) in comparison to the adjacentlayers is. It is preferred that the refractive index of the firstoptically transparent layer (a) is higher than 1.8.

A further important requirement on the properties of the layer (a) is,that the propagation losses of the light guided in said layer are as lowas possible. It is preferred that the first optically transparent layer(a) comprises a material of the group of TiO₂, ZnO, Nb₂O₅, Ta₂O₅, HfO₂,or ZrO₂, especially preferred of TiO₂ or Nb₂O₅ or Ta₂O₅. Combinations ofseveral such materials can also be used.

For a given material of the layer (a) and a given refractive index thesensitivity is the better, the smaller the layer thickness is, as longas the layer thickness is larger than a lower limiting value. The lowerlimiting value is determined by the cease of light-guiding upon decreaseof the layer thickness below a value that is dependent on the wavelengthof the light to be guided and by an increase of the propagation losseswith decreasing layer thickness in case of very thin layers. It is ofadvantage, if the product of the thickness of layer (a) and itsrefractive index is one tenth up to a whole, preferably one third to twothirds of the excitation wavelength of an excitation light to be coupledinto layer (a).

Characteristic for a special embodiment of the sensor platform, as apart of the optical system according to the invention, is that a thinmetal layer, preferably of gold or silver, optionally on an additionaldielectric layer with lower refractive index than layer (a), for exampleof silica or magnesium fluoride, is deposited between the opticallytransparent layer (a) and the immobilized biological or biochemical orsynthetic recognition elements, wherein the thickness of the metal layerand of the optional additional intermediate layer is selected in such away that surface plasmon can be excited at the excitation and/or theluminescence wavelength.

It is preferred that optically or mechanically recognizable marks forsimplifying adjustments in an optical system and/or for the connectionto sample compartments as part of an analytical system and/or as helpsfor a later image analysis are provided on the sensor platform, as apart of the optical system according to the invention.

For the routine-type handling of a multitude of sensor platforms,perhaps provided in different embodiments, as well as for the guaranteeof a continuously high product quality, the retraceability of thehistory of manufacturing and use of a sensor platform is of highimportance. Therefore it is preferred that the sensor platform, as apart of the optical system according to the invention, is provided witha mark, such as a barcode, which can be read by a barcode readerintegrated into the optical system.

A variety of further embodiments of sensor platforms, which are suitedas a part of an optical system according to the invention, are describedin detail, for example in U.S. Pat. No. 5,822,472, No. 5,959,292, andNo. 6,078,705, and in the patent applications WP 96/35940, WO 97/37211,WO 98/08077, WO 99/58963, PCT/EP 00/04869, and PCT/EP 00/07529. Theembodiments of sensor platforms and of methods of determination of oneor more analytes by luminescence detection are also part of the presentinvention upon use of an optical system according to the presentinvention.

In principle, an optical system according to the invention can beoperated both with monochromatic and with polychromatic light sources.It is preferred, however, that the excitation light from the two or morelight sources is always essentially monochromatic.

Characteristic for a special embodiment of the optical system accordingto the invention is, that the excitation light from different lightsources is irradiated simultaneously from different directions towardsthe sensor platform in such a way, that the offset between the beamcenters on the sensor platform is less than 0.2 mm.

The detection beam path of the optical system according to the inventioncan be designed in such a way, that optical components of the groupcomprising lenses or lens systems for the shaping of the transmittedlight bundles, planar or curved mirrors for the deflection andoptionally additional shaping of the light bundles, prisms for thedeflection and optionally spectral separation of the light bundles,dichroic mirrors for the spectrally selective deflection of parts of thelight bundles, neutral density filters for the regulation of thetransmitted light intensity, optical filters or monochromators for thespectrally selective transmission of parts of the light bundles, orpolarization selective elements for the selection of discretepolarization directions of the excitation or luminescence light arelocated between the sensor platform and the one or more detectors.

The light excitation can be performed continuously (cw). It ispreferred, however, that the excitation light is launched in pulses witha duration of 1 fsec to 10 min.

Characteristic for an improvement of the optical system according to theinvention is, that the emission light from the measurement areas ismeasured time-resolved.

It is preferred, that for referencing purposes light signals of thegroup comprising excitation light at the location of the light sourcesor after expansion of the excitation light or after its multiplexinginto individual beams, scattered light at the excitation wavelength fromthe location of the one or more laterally separated measurement areas,and light of the excitation wavelength out-coupled by the gratingstructure (c) besides the measurement areas are measured. Thereby, themeasurement areas for determination of the emission light and of thereference signal can overlap partly or completely, whereas preferablythey are identical.

In general, the excitation beam path of the optical system according tothe invention, concerning that part of the beam path until the launch ofthe excitation light onto said optical component with several discretefacets for beam deflection described above, is determined and fixed whenthe optical components are assembled and remains essentially unchangedthereafter, except for, e.g., thermally caused minor fluctuations.Therefore, it is also possible to measure once the distribution of theexcitation light intensity in the beam path before said opticalcomponent for beam deflection and to store this distribution as aspecific system function (instrument function) for purposes ofreferencing, which can be treated (taken into account) like a referencesignal for a data correction. The measurement of this distribution ofthe excitation light can be repeated in adequate temporal intervals, ifnecessary, and be stored as a new instrument function.

When the emission beam profiles of the light sources and the opticalproperties of the optical components provided in the beam path areprecisely known, it is even possible to calculate the distribution ofthe excitation light mathematically and store it as an instrumentfunction, which can be treated (taken into account) like a referencesignal for a data correction.

As described above, sensor platforms based on thin-film waveguides andon in-coupling of the excitation light by means of a diffractive gratingmodulated in the waveguiding layer are characterized by a resonanceangle with an only very small half-width for the in-coupling. Especiallyfor embodiments of the inventive optical systems with such type ofsensor platforms it is advantageous, if the optimization of theadjustment for optimum in-coupling of excitation light by means of anin-coupling grating (c) towards measurement areas provided in directionof propagation of the in-coupled light is performed upon maximization ofthe excitation light out-coupled by an out-coupling grating (c′) andmeasured by a detector, wherein this optimization is preferablyperformed under computer control.

Characteristic for a special embodiment of the optical system accordingto the invention is, that a rotation of the optical component withseveral discrete facets for beam deflection, around an axis locatedinside or outside of said optical component, is performed for theoptimization of the adjustment of the coupling angle. Thereby it ispreferred, that the optical component with several discrete facets forbeam deflection is connected with a rotary element with axis of rotationinside or outside of said optical component in such a way, that theoffset of the beam on the sensor platform is less than 0.3 mm upon arotation of said optical component around said axis of rotation by lessthan 5°.

Characteristic for many possible embodiments of the optical systemaccording to the invention is, that a translation of the sensor platformin parallel or perpendicular to the grating lines is performed foroptimization of the coupling position.

It is preferred, that the optimization of the adjustment is performedupon maximization of one or more reference signals from one or moremeasurement areas on the sensor platform, wherein this optimization ispreferably performed under computer control.

Thereby, it is characteristic for one possible embodiment, that saidreference signal is scattered light of the excitation wavelength.However, it is also possible that said reference signal is luminescencelight from measurement areas dedicated for purposes of referencingand/or of adjustment.

In one embodiment of the optical system according to the invention,light irradiation and acquisition of the emission light from a pluralityof measurement areas or from on or from multiple arrays of measurementareas or even from all measurement areas are performed simultaneously.Characteristic for another embodiment is, that the irradiation of theexcitation light to and detection of emission light from one or moremeasurement areas is performed sequentially for one or more measurementareas. It is also possible, sequential irradiation of the excitationlight and detection of the emission light from one or more measurementareas is performed multiple times (for these measurement areas).

In case of sequential detection of luminescence from differentmeasurement areas a locally resolving detector is not mandatory, but inthis case a simple detector, such as a conventional photomultiplier or aphotodiode or an avalanche photodiode can be used.

Characteristic for another embodiment of an optical system according tothe invention is, that such inventive arrangement is moved between stepsof sequential excitation and detection.

A further subject of the invention is an analytical system, for thedetermination of one or more analytes in at least one sample on one ormore measurement areas on a sensor platform by luminescence detection,comprising an optical system according to the invention and according toany the embodiments disclosed above and supply means for bringing theone or more samples into contact with the measurement areas on thesensor platform.

Thereby it is preferred that the analytical system according to theinvention additionally comprises one or more sample compartments, whichare at least in the area of the one or more measurement areas or of themeasurement areas combined to segments open towards the sensor platform.Thereby the sample compartments can have a volume of 0.1 nl-100 μl each.

Characteristic for a preferred embodiment of the analytical systemaccording to the invention is, that the sample compartments are closed,except for inlet and/or outlet openings for the supply or outlet ofsamples, at their side opposite to the optically transparent layer (a),and wherein the supply or the outlet of the samples and optionally ofadditional reagents is performed in a closed flow-through system,wherein, in case of liquid supply to several measurement areas orsegments with common inlet and outlet openings, these openings arepreferably addressed row by row or column by column.

Another possible embodiment consists in that the supply of the samplesand optionally of additional reagents is performed in parallel orcrossed micro-channels, upon exposure to pressure differences or toelectric or electromagnetic potentials.

Characteristic for another preferred embodiment of the analytical systemaccording to the invention is, that the sample compartments are providedwith openings at the side facing away from the optically transparentlayer (a), for locally addressed supply or removal of the samples or ofother reagents.

It is preferred, that the sample compartments are arranged in an array,comprising the sensor platform as the base plate and a body combinedtherewith in such a way, that an array of cavities is generated betweenthe base plate and said body, for generation of an array of flow cellsfluidically sealed against each other, and that at least one outlet ofeach flow cell leads to a reservoir fluidically connected with said flowcell and capable to receive liquid exiting from said flow cell. Therebyit is advantageous, if the reservoir for receiving liquid exiting fromthe flow cell is provided as a recess in the exterior wall of the bodycombined with the base plate.

The analytical system according to the invention can principallycomprise almost any number of sample compartments, typically 2-2000,preferably 2-400, most preferably 2-100 sample compartments.

It is preferred, that the pitch (geometrical arrangement in rows and/orcolumns) of the inlets of the sample compartments does correspond to thepitch (geometrical arrangement) of the wells of a standard microtiterplate.

It is also preferred, that the arrangement of sample compartments withthe sensor platform as the base plate and the body combined therewithdoes correspond to the footprint of a standard microtiter plate.

Characteristic for another embodiment of the analytical system accordingto the invention with, for example, 2 to 8 sample compartments in acolumn or, for example, 2 to 12 sample compartments in a row, is thatsaid sample compartments in a column or row themselves are combined witha carrier (“meta-carrier”) with the dimensions of standard microtiterplates in such a way, that the pitch (geometrical arrangement in rowsand/or columns) of the inlets of the flow cells does correspond to thepitch (geometrical arrangement) of the wells of a standard microtiterplate.

Characteristic for a further variant of the analytical system accordingto the invention is, that a removable bottom protection is providedbelow the sensor platform as the base plate of an arrangement of samplecompartments, and wherein optionally the upper side of the arrangementof sample compartments is closed with an additional covering top, forexample a film, a membrane or a cover plate. Thereby it is preferred,that the bottom protection is removed automatically orsemi-automatically before a measurement is started.

A preferred embodiment of an analytical system according to theinvention, comprising an optical system according to any of thedisclosed embodiments, is characterized in that at least one gratingstructure (c) modulated in the waveguiding layer (a) of a sensorplatform as the base plate, for the in-coupling of excitation lighttowards the measurement areas, is provided within each samplecompartment.

Characteristic for one possible embodiment is, that grating structures(c) are provided within the range of the sample compartments andadditional grating structures (c′) for light out-coupling are alwaysarranged outside of those sample compartments where the in-coupling isperformed.

Characteristic for another possible embodiment of the analytical systemaccording to the invention is, that grating structures (c) and optionaladditional grating structures (c′) extend over the range of several orof all sample compartments.

It is preferred, that 5-5000, preferably 10-400 measurement areas areprovided in one sample compartment.

Characteristic for an improvement of the analytical system according tothe invention is, that additionally mechanical means and a transportmechanism are provided, operable for an automated transport of anarrangement of sample compartments, comprising a sensor platform as abase plate and a body combined therewith, from a location of theinsertion of that arrangement to the location of luminescence excitationand detection and optionally from there back to the original position.

Another improvement consists in that said analytical system additionallycomprises a receiving device (“stacker”) for receiving a plurality ofarrangements of sample compartments.

Thereby it is preferred that the loading of the “stacker” from theposition of the insertion of the arrangement of sample compartments andthe transport of said arrangement of sample compartments from there tothe location of luminescence excitation and detection and then back tothe original location is performed automatically.

Characteristic for another embodiment of the analytical system accordingto the invention is, that said analytical system comprises one or moretemperature-controllable zones. Thereby it is preferred, that thearrangement of sample compartments and/or the excitation light sourcesand/or the one or more opto-electronic detectors and/or the “stacker”can be temperature-controlled separately. This allows, for example, tocool biological samples until the moment and thus to prevent or reduce apossible degradation of contained components. The signal stability ofopto-electronic devices is also generally effected in a positive way bytemperature control.

Characteristic for another variant of the analytical system according tothe invention is, that the arrangement of sample compartments and/or theexcitation light sources and/or the one or more opto-electronicdetectors and/or the “stacker” are operated under a higher air pressurethan ambient pressure. Thus can, for example, the penetration of dustinto the system be prevented.

For the various embodiment of the analytical system according to theinvention it is preferred, that said analytical system additionallycomprises one or more electronic control components for control of thestatus of one or more optical or electrical or mechanical components,which control components can generate an optical or acoustic orelectronic alarm signal if necessary.

It is also advantageous, if the analytical system according to theinvention comprises means for preventing the insertion of not adequatesensor platforms, for example with wrong mechanical dimensions.

For the conduction of a large number of studies and measurements and forimprovement of their reproducibility, a high degree of automation isgenerally desirable. Therefore it is preferred, that the analyticalsystem according to the invention additionally comprises one or moreelectronic processors, connected to storage media and electronicconnecting media, a keyboard for data or command input, a screen and aprogram code for automated operation.

Especially for routine-type working processes it is also preferred, thatthe operation of said analytical system and/or the measurement areperformed automatically using pre-defined files for initialization. Itis advantageous, if the analytical system according to the invention isreset automatically to a pre-defined initial status and possiblygenerated measurement data are secured in a file, when an indicatederror function has occurred.

Characteristic for an improvement of the analytical system according tothe invention is, that a file is generated automatically for eachmeasurement, in which file are stored the code of the used sensorplatform, the essential measurement parameters and the measurement data.

Characteristic for another advantageous improvement is, that localvariations of the excitation light intensity on the sensor platformand/or of the detection sensitivity of the optical system for lightsignals from different positions on the sensor platform are correctedusing means which comprise, for example, the recording of images forcorrection taken at the excitation wavelength and/or at one or moreluminescence wavelengths, the calculation of theoretical distributionsof the available excitation light intensity, theoretical calculations ofthe locally resolved efficiency of the optical imaging and detectionsystem, etc.

A further subject of the invention is a method for the determination ofone or more analytes by luminescence detection, upon using an analyticalsystem according to the invention which comprises an optical systemaccording to the invention, wherein one or more liquid samples to beanalyzed for the one or more analytes are brought into contact with oneor more measurement areas on the sensor platform, excitation light isdirected towards the measurement areas, thus exciting compounds capableof luminescence in the sample or on the measurement areas toluminescence and the emitted luminescence is measured.

The method according to the invention includes, that, for generation ofluminescence, at least one luminescent dye or luminescent nanoparticleis used as a luminescence label, which can be excited and emits at awavelength between 300 nm and 1100 nm.

Characteristic for an advantageous embodiment of the method is, that itcomprises means to extend the dynamic range for signal recording by atleast a factor of 3.

Said means for extending the dynamic range can comprise, for example,the application of differently long exposure times, i.e., the durationof the irradiation of the excitation light and the integration time ofthe detector, which exposure times can be varied by at least a factor of3.

As another possibility, the means for extending the dynamic range cancomprise a variation of the excitation light available on the sensorplatform by at least a factor of 3, for example upon using discreteneutral density filters in the excitation beam path, optionally providedas a “continuously varying” filter with a continuous local gradient ofthe transmission, or upon variation of the intensity of the lightsources or upon changing the adjustment of the sensor platform withrespect to the excitation beam path.

In general, it is characteristic for the method according to theinvention, that the at least one luminescence label is bound to theanalyte or, in a competitive assay, to an analyte analogue or, in amulti-step assay, to one of the binding partners of the immobilizedbiological or biochemical or synthetic recognition elements or to thebiological or biochemical or synthetic recognition elements.

Characteristic for an improvement of the method is, that a second ormore luminescence labels of similar or different excitation wavelengthas the first luminescence label and similar or different emissionwavelength are used.

Characteristic for another possible embodiment of the method accordingto the invention is, that charge or optical energy transfer from a firstluminescent dye acting as a donor to a second luminescent dye acting asan acceptor is used for the detection of the analyte.

Characteristic for another advantageous embodiment of the method is,that the one or more luminescences and/or determinations of lightsignals at the excitation wavelengths are performedpolarization-selective. Thereby it is preferred, that the one or moreluminescences are measured at a polarization that is different from theone of the excitation light.

The method according to the invention is suited for the simultaneous orsequential, quantitative or qualitative determination of one or moreanalytes of the group comprising antibodies or antigens, receptors orligands, chelators or “histidin-tag components”, oligonucleotides, DNAor RNA strands, DNA or RNA analogues, enzymes, enzyme cofactors orinhibitors, lectins and carbohydrates.

It is also characteristic for possible embodiments of the method, thatthe samples to be examined are naturally occurring body fluids, such asblood, serum, plasma, lymph or urine, or egg yolk or optically turbidliquids or tissue fluids or surface water or soil or plant extracts orbio- or process broths, or are taken from biological tissue fractions orfrom cell cultures or cell extracts.

A further subject of the invention is the use of an optical systemaccording to the invention and/or of an analytical system according tothe invention and/or of a method according to the invention for thequantitative or qualitative analyses for the determination of chemical,biochemical or biological analytes in screening methods inpharmaceutical research, combinatorial chemistry, clinical andpre-clinical development, for real-time binding studies and for thedetermination of kinetic parameters in affinity screening and inresearch, for qualitative and quantitative analyte determinations,especially for DNA- and RNA analytics, for generation of toxicitystudies and for the determination of gene and protein expressionprofiles, and for the determination of antibodies, antigens, pathogensor bacteria in pharmaceutical product development and research, humanand veterinary diagnostics, agrochemical product development andresearch, for symptomatic and pre-symptomatic plant diagnostics, forpatient stratification in pharmaceutical product development and for thetherapeutic drug selection, for the determination of pathogens, nocuousagents and germs, especially of salmonella, prions and bacteria, in foodand environmental analytics.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an illustration of the sensor platform.

FIG. 2 is an illustration of the optical system comprising the sensorplatform.

The invention is further explained by the following examples.

EXAMPLE 1 1A: Sensor Platform

A sensor platform with the exterior dimensions of 75 mm width×113.5 mmlength×0.7 mm thickness is used, on the surface of which 96 micro flowcells, with inside dimensions of 8 mm width×8 mm length×0.15 mm height,in the pitch (arrangement in rows and columns) of a classical microtiterplate (Pitch: 9 mm) can be arranged, by combination of said sensorplatform with a polycarbonate plate having open recesses facing thesensor platform. The polycarbonate plate can be glued to the sensorplatform in such a way, that the recesses are then tightly sealedagainst each other.

The substrate material (optically transparent layer (b)) consists of AF45 glass (refractive index n=1.52 at 633 nm). A periodic sequence(screen) of pairs of in- and out-coupling gratings, with grating lines(318 nm period) in parallel to the width of the sensor platform, with agrating depth of 12+/−3 nm, is generated in the substrate, wherein thegrating lines extend over the whole width of the sensor platform. Thedistance between subsequent grating pairs is 9 mm; the length of theindividual grating structures (in parallel to the length of the sensorplatform) is 0.5 mm. The distance between the in- and the out-couplinggrating of a grating pair is 5.5 mm, allowing for in- and out-couplingof the excitation light always within the (inside) region of the samplecompartments, after combination of the sensor platform with thepolycarbonate plate described above. The waveguiding, opticallytransparent layer (a) of Ta₂O₅ on the optically transparent layer (b)has a refractive index of 2.15 at 633 nm (layer thickness 150 nm).

The sample compartments formed by the combination of the sensor platformwith the polycarbonate plate are provided with conically bored openingsat the demarcation surface opposite to the sensor platform, thusallowing for a filling or clearing of the sample compartments byinserting standard-type, commercially available pipette tips ofpolypropylene.

As a preparation for the immobilization of the biochemical or biologicalor synthetic recognition elements, the senor platforms are cleaned withchloroform in an ultrasonic apparatus, chemically activated by asilanization reaction with glycidyloxypropyltrimethoxy silane, and thusprepared for the immobilization of the probe cDNAs as biologicalrecognition elements. The individual cDNAs, at a concentration of 50ng/μl, are deposited as spots of 10 drops (0.1 nl) each, using acommercial, piezo-controlled micropipette (GeSIM, Groβerkmannsdorf, DE),resulting in spots as discrete measurement areas of about 150 μm.

In a 10×10 spot arrangement (array of 100 features), always 4measurement areas with the same cDNA are provided in a way that, at theend of the immobilization step, an array always comprises measurementareas with 25 different recognition elements with four replicates foreach recognition element. The spots are provided at a distance(center-to-center) of 400 μm. Thus, an individual array covers an areaof about 4×4 mm², wherein the area is arranged at short distance (about2 mm) to a grating structure (c), which is used in the later analyticaldetection method as the in-coupling grating for the excitation light.For the later analysis of a plurality of samples on identical arrays, amultitude of identical arrays is generated on the sensor platform at apitch of 9 mm in a way as described above.

The described polycarbonate plate is combined with the prepared sensorplatform in such a way, that the individual sample compartments arefluidically tightly sealed against each other and that the arrays withthe corresponding in-coupling gratings (c) are always located within thesample compartments.

1B: Optical Beam Path

The beam path for excitation light of different wavelength, passingthrough an optical component for beam deflection and propagating towardsthe in-coupling grating of a sensor platform, is shown schematically,i.e. not according to scale and not isogonal, in FIG. 1.

A multi-facet prism, as an example of an optical component with severaldiscrete facets for beam deflection, is denoted with (1). (2) indicatesthe beam path of shorter-wavelength, e.g. blue excitation light throughthe lower facet towards the in-coupling grating (4) (corresponding to agrating structure (c) according to the above disclosure of theinvention) of the sensor platform, (3) denotes the beam path of alonger-wavelength, e.g. red excitation light.

With the layer and grating parameters of the sensor platform describedin Example 1A, the in-coupling angle for excitation light of 492 nm isabout +18.2° and for excitation light of 670 nm about −17.4° (with airas the medium above the coupling grating). Consequently, the divergenceangle between light beams of these excitation wavelengths is 35.6°, whenthe corresponding in-coupling conditions are satisfied. The multi-facetprism, as a part of the optical system according to the invention, isdesigned in such a way that, before entrance of the light into theprism, the angle between the irradiated short-wavelength excitationlight and the plane (5 a) parallel to the plane of the sensor platformsurface is 27.3°, whereas, before entrance of the light into the prism,the angle between the irradiated long-wavelength excitation light andthe plane (5 b) parallel to the sensor platform surface is 1.9°.Consequently, the original angular divergence, before entrance of thelight beams into the prism, is only 25.9°. Thus, the divergence angle isincreased, in this example, by a factor of 1.37, by using themulti-facet prism as part of the optical system according to theinvention. Additionally, the excitation light beams of both wavelengthshit the in-coupling grating (4) on the sensor platform at the samelocation. Thus, an in-coupling without a change of the position of thesensor platform is enabled.

The multi-facet prism is mounted on a goniometer (not shown in FIG. 1)in such a way, that a rotation by less than 5° leads to an offset of thebeam centers on the sensor platform below 0.3 mm.

Additionally, the angle of beam spread (6), under which maximum angleluminescence light emanating from the sensor platform can be imaged ontothe detector (9) by means of a tandem objective with an entranceobjective (7 a) and an exit objective (7 b), is schematically indicatedin FIG. 1. One or more interference filters (8) for spectral selectionof the detection wavelength are located between the two halves of thetandem objective, in that part of the emission beam path with isparallel in the ideal case. By means of this arrangement a part of theisotropically emitted light emanating from the sensor platform iscollected and directed onto the detector (9).

1C: Analytical System

Parts of an exemplary embodiment of an analytical system according tothe invention, including essential components of an optical systemaccording to the invention, are shown in FIG. 2. The spatial directionsx/y/z are indicated in the figure.

With (10) is shown in the most upper part of FIG. 2 an inventive devicecomprising a sensor platform and sample compartments provided in theembodiment with the external dimensions of a microtiter plate, whichdevice can be moved in x-direction and y-direction, with respect to thedirection of propagation of the excitation light, by means of steppingmotors (11 a, 11 b). Separated from ambience by a sheet-metal hood, thispart of the analytical system can be temperature-controlled separately.

Adjacent below is located a further section, comprising a row of mirrorswith the corresponding mounts and adjustment means, 12 a, 12 b, 12 c,for the deflection of the excitation light, preferably from laser lightsources, towards one of the entrance facets of a multi-facet prism 1.During assembly of the system, the mirrors 12 a-c are adjusted to therequired direction of light irradiation onto the dedicated entrancefacet of the multi-facet prism in a way that, after passing of the beamthrough the multi-facet prism, the resonance condition for thecorresponding excitation wavelength, for in-coupling of said excitationlight into the waveguiding layer of a sensor platform by means of agrating structure (4) can be satisfied. In case of necessary service,these mirrors can be adjusted in x- and y-direction. In each of the beampaths between mirrors 12 a-c and the multi-facet prism are provideddiaphragms (not shown in FIG. 2), which can be used to limit theexcitation light bundle to the desired geometrical dimensions.Additionally, a filter wheel (13), for regulating the excitation lightintensity by means of discrete neutral density filters of differenttransmissions, is provided in this section. In case of (spectrally)broad-band excitation light sources or upon use of lasers with multipleemission lines, one or more positions in the filter wheel 13 can also beused for interference filters or for edge filters of adequatetransmission wavelength.

At the right part of this section is located a further filter wheel (14)for the selection of those wavelengths, at which the signal acquisitionof the light emanating from the sensor platform shall be performed,using interference filters (8). Signal acquisition can be performed bothat the emission wavelengths of the excited one or more luminescences andat emission wavelengths of the excitation light sources, optionallycombined with the use of neutral density filters for attenuation of thelight intensity. In an exemplary embodiment of the system themeasurement of the light at the excitation wavelengths emanating fromthe sensor platform is performed using preferably narrow-band filters(i.e. <10 nm width of transmission) with the following centraltransmission wavelengths:

-   -   A) 635 nm (laser emission wavelength: 635 nm)    -   B) 532 nm (laser emission wavelength: 532 nm)    -   C) 492 nm (laser emission wavelength: 492 nm).

In case of weak luminescences, the intensity of which is negligible incomparison to the excited luminescence, the use of spectrally selectivefilters for light at the excitation wavelength is dispensable. It isalso possible to avoid the risk of a saturation of the detector (9) byrecording signals at the excitation wavelength using shorter exposuretimes and/or a reduced excitation light intensity by means of anadequate neutral density filter in the filter wheel 13. Then the use offilters in the filter wheel 14, for detection at the excitationwavelength, can also be dispensable.

For detection of the luminescence light excited at the wavelengthsdenoted under A) to C) the corresponding filters D)-F) are used:

-   -   D) filter for signal acquisition from luminescence in the range        from 650-700 nm, excited at 635 nm    -   E) filter for signal acquisition from luminescence in the range        from 540-590 nm, excited at 532 nm    -   F) filter for signal acquisition from luminescence in the range        from 500-550 nm, excited at 492 nm

Above the filter wheel (14) is located the entrance objective (7 a) of atandem objective, below the filter wheel the exit objective (7 b) of atandem objective.

In the section below are located mirrors 15 a, 15 b, and 15 c, for thedeflection of the excitation light which is preferably irradiateddirectly onto these mirrors. These mirrors 15 a-c are preferably mountedwith an offset with respect to each other and adjusted in such a way,that the excitation light with the adequate spatial direction isdirected onto the corresponding mirrors 12 a-c in a way to allow tosatisfaction of the resonance condition for the corresponding excitationwavelength, for in-coupling of said excitation light into thewaveguiding layer of a sensor platform by means of a grating structure(4). The exemplary arrangement of the mirrors 12 a-c and 15 a-c allows,in especial, also the simultaneous irradiation of excitation ofdifferent wavelengths, if the beam offset between these excitationlights on the sensor platform is sufficiently small. (Thereby anexpansion of the arrangement to a larger number of light sources and toadditional optical components for beam deflection is part of the presentinvention). In case of necessary service the mirrors 15 a-c can beadjusted in z-direction.

Of course all mirrors mentioned above can be substituted, with respectto their function, by other beam-deflecting optical components, such asprisms.

The whole part of this section shown on the right, which is preferablytemperature-controlled separately, is occupied in this exemplaryembodiment by the detector (9), which is preferably a locally resolvingdetector, whereby a CCD camera is specially preferred.

The excitation light sources (not shown in the figure), from where, at apart of this section masked in this embodiment, the excitation light isemitted, are adjusted in such a way that the light beams arrive at themirrors 15 a-c at the adequate spatial orientation, that, after beampath through the other optical elements in the excitation light pathdescribed above, the resonance condition for the correspondingexcitation wavelength, for in-coupling of said excitation light into thewaveguiding layer of a sensor platform by means of a grating structure(4) can be satisfied.

In an exemplary embodiment of the system lasers or laserdiodes with mainemission wavelengths at 635, 532, and 492 nm are used.

With (16) is denoted in the left lower part of the bottom section anarrangement of ventilators, which are used for air supply to the systemor for removal of air from the system, especially to enable orfacilitate the temperature control of the different segments of thesystem.

On the right side of FIG. 2 is shown a stacker (17), which canaccommodate a plurality of inventive sensor platforms respectively ofassemblies of sensor platforms and corresponding sample compartments,especially to enable the sequential conduction of a multitude ofmeasurements. Preferably, this stacker is designed for accommodatingsuch components with external dimensions of standard microtiter plates.The insertion of the components is performed at the insertion region(18), which additionally comprises a cover and a device for removing anoptional bottom protection of the inventive sensor platform (not shownin this figure). By means of a photo sensor (also not shown) located inthe insertion region it is controlled, if there is a sensor platformprovided, if said sensor platform meets the external dimensionsacceptable for the system, and if the sensor platform has been insertedat the correct orientation into the insertion region.

The section of the stacker can also be temperature-controlledseparately, if necessary. The insertion of the sensor platforms into theinsertion region (18) can be performed manually or also under computercontrol using an adequate robotic arm.

1. An optical system for luminescence determination, comprising at leasttwo excitation light sources, a sensor platform which comprises amultitude of discrete measurement areas, and an optical component withseveral discrete facets for deflecting a light beam arranged such thatthe angle of divergence between excitation light falling onto differentfacets of said optical component is increased or reduced by at least afactor of 1.2 in the optical path departing from said optical component,in comparison to the original divergence angle between said light raysirradiated onto said different facets, whereby said sensor platform is aplanar optical waveguide and said planar optical waveguide comprises afirst optically transparent layer on a second optically transparentlayer and wherein the second optically transparent layer has a lowerrefractive index than the first optically transparent layer whichcomprises at least one first diffractive grating structure modulatedtherein for in-coupling of excitation light and the sensor platform ischaracterized by a coupling angle wherein resonance condition forin-coupling into the first optically transparent layer is met.
 2. Theoptical system according to claim 1, wherein the angle of divergencebetween excitation light falling onto different facets of said opticalcomponent is increased by at least a factor of 1.2 in the optical pathdeparting from said optical component, in comparison to the originaldivergence angle between said light rays irradiated onto said differentfacets.
 3. The optical system according to claim 1, wherein said opticalcomponent with several discrete facets for beam deflection is amulti-facet mirror with planar or curved facets, preferably with planarfacets.
 4. The optical system according to claim 1, wherein said opticalcomponent with several discrete facets for beam deflection is amulti-facet prism with planar or curved facets.
 5. The optical systemaccording to claim 1, wherein the light from two or more excitationlight sources of similar or different wavelength falls onto the samefacet of said optical component for beam deflection.
 6. The opticalsystem according to claim 1, wherein a dedicated facet of said opticalcomponent is provided for each different excitation wavelength, theexcitation light of said excitation wavelength to be directed onto thecorresponding dedicated facet for beam deflection.
 7. The optical systemaccording to claim 1, wherein the beam deflection of excitation light ofdifferent wavelength into different predefined directions occurs with anoffset of less than 0.2 mm between the centers of the deflected beams onthe sensor platform.
 8. The optical system according to claim 4, whereinthe multi-facet prism comprises additional means for deflecting ormasking reflections of the excitation light emanating from the sensorplatform.
 9. The optical system according to claim 4, wherein one ormore reflective facets of the multi-facet prism are partly or completelymetallized.
 10. The optical system according to claim 1, whereinadditional optical elements for the spectral selection of the excitationwavelength are located in the optical path of the excitation lightbetween the at least one excitation light source and the opticalcomponent with several discrete facets for beam deflection.
 11. Theoptical system according to claim 1, wherein two or more lasers withdifferent emission wavelengths are used as excitation light sources. 12.The optical system according to claim 1, wherein additional opticalelements comprising diffractive optical elements and/or lenses for beamexpansion and/or for generation of a parallel beam and/or diaphragms ormasks for partial masking of the beam are located in the optical path ofthe excitation light between the light sources and the sensor platform,in order to generate a desired beam profile on the sensor platform. 13.The optical system according to claim 1, wherein in the multitude ofdiscrete measurement areas biological or biochemical or syntheticrecognition elements for the determination of one or more analytes areimmobilized.
 14. The optical system according to claim 1, wherein up to100,000 measurement areas are provided in a two-dimensional arrangementon the sensor platform.
 15. The optical system according to claim 1,wherein a single measurement area has an area of 0.001 mm²-6 mm². 16.The optical system according to claim 13, wherein an adhesion-promotinglayer is deposited between the biological or biochemical or syntheticrecognition elements and the sensor platform.
 17. The optical systemaccording to claim 16, wherein the adhesion-promoting layer has athickness of less than 200 nm, and wherein the adhesion-promoting layercomprises a chemical compound of the groups comprising silanes,epoxides, functionalized, charged or polar polymers, and “self-organizedpassive or functionalized mono- or double-layers”.
 18. The opticalsystem according to claim 13, wherein the multitude of discretemeasurement areas are laterally separated and are generated on thesensor platform by laterally selective deposition of the biological orbiochemical or synthetic recognition elements on said sensor platform.19. The optical system according to claim 13, wherein, as saidbiological or biochemical or synthetic recognition elements, componentsof the group formed by nucleic acids and nucleic acid analogues, mono-or polyclonal antibodies, peptides, enzymes, aptamers, synthetic peptidestructures, soluble membrane-bound proteins and proteins isolated from amembrane, receptors, their ligands, antigens for antibodies,“histidin-tag components” and their complex forming partners, cavitiesgenerated by chemical synthesis, for hosting molecular imprints.
 20. Theoptical system according to claim 13, wherein whole cells, cellcomponents, cell membranes or their fragments are deposited asbiological or biochemical or synthetic recognition elements.
 21. Theoptical system according to claim 18, wherein regions between thelaterally separated measurement areas are “passivated” for minimizationof non-specific binding of analytes or their tracer compounds.
 22. Theoptical system according to claim 1, wherein the luminescence light fromthe measurement areas on the sensor platform is directed onto at leastone opto-electronic detector.
 23. The optical system according to claim1, wherein the luminescence light from the measurement areas is imagedonto a locally resolving detector.
 24. The optical system according toclaim 1, wherein the luminescence light from the measurement areas isimaged onto the at least one opto-electronic detector by means of asystem comprising one or more lenses and/or mirrors.
 25. The opticalsystem according to claim 1, wherein one or more optical elements forselection of the emission wavelength and discrimination of light ofother wavelengths are provided in the emission beam path between thesensor platform and the at least one opto-electronic detector forrecording the luminescence light emanating from the measurement areas.26. The optical system according to claim 25, wherein the emission beampath has a divergence or convergence of less than 15° at the position ofapplication of said optical element for the spectral selection.
 27. Theoptical system according to claim 25, wherein the optical elements forselection of the emission wavelength and for discrimination of light ofother wavelengths are located between the two halves of a tandemobjective.
 28. The optical system according to claim 1, wherein thesensor platform comprises an optically transparent support on which thebiological or biochemical or synthetic recognition elements areimmobilized in the measurement areas.
 29. The optical system accordingto claim 1, wherein the first diffractive grating structures aremodulated in the first optically transparent layer of the sensorplatform being arranged in a one- or two-dimensional array, with even,non-modulated regions of the first optically transparent layer beingadjacent to the first diffractive grating structures modulated thereinin the direction of propagation of an excitation light to be in-coupledinto the first optically transparent layer, and wherein arrays of two ormore measurement areas are provided on these non-modulated regions. 30.The optical system according to claim 1, wherein second diffractivegrating structures for the out-coupling of excitation light are providedon the sensor platform, in addition to first diffractive gratingstructures for the in-coupling of excitation light, in order toout-couple again the light guided in the first optically transparentlayer, after its passing through the region of the measurement areas indirection of propagation of the guided excitation light following anin-coupling first diffractive grating structure.
 31. The optical systemaccording to claim 1, wherein the first diffractive grating structuresand optionally second diffractive grating structures are provideddiscretely for individual segments by arrangement in one- ortwo-dimensional arrays of measurement areas.
 32. The optical systemaccording to claim 1, wherein the first diffractive grating structuresare provided as continuous strips (columns) extending over the wholesensor platform perpendicular to the direction of propagation of theexcitation light to be in-coupled.
 33. The optical system according toclaim 30, wherein the second diffractive grating structures are alsoused as in-coupling first diffractive gratings upon sequentialperformance of measurements.
 34. The optical system according to claim30, wherein the first diffractive grating structures for the in-couplingand second diffractive grating structures for the out-coupling of lightout of the first optically transparent layer of the sensor platform havethe same period and are modulated continuously below all measurementareas of the sensor platform.
 35. The optical system according to claim1, wherein the product of thickness of the first optically transparentlayer times its refractive index is one tenth up to a whole of thewavelength of any excitation light to be coupled into the firstoptically transparent layer.
 36. The optical system according to claim13, wherein a thin metal layer is deposited between the first opticallytransparent layer and the immobilized biological or biochemical orsynthetic recognition elements, wherein the thickness of the metal layeris selected in such a way that surface plasmon can be excited at theexcitation and/or the luminescence wavelength.
 37. The optical systemaccording to claim 1, wherein optically or mechanically recognizablemarks for simplifying adjustments in an optical system and/or for theconnection to sample compartments as part of an analytical system and/oras helps for a later image analysis are provided on the sensor platform.38. The optical system according to claim 1, wherein the excitationlight from the two or more light sources is essentially monochromatic.39. The optical system according to claim 1, wherein the excitationlight from different light sources is irradiated simultaneously fromdifferent directions towards the sensor platform in such a way, that theoffset between the beam centers on the sensor platform is less than 0.2mm.
 40. The optical system according to claim 1, wherein opticalcomponents of the group comprising lenses or lens systems for theshaping of the transmitted light bundles, planar or curved mirrors forthe deflection, prisms for the deflection, dichroic mirrors for thespectrally selective deflection of parts of the light bundles, neutraldensity filters for the regulation of the transmitted light intensity,optical filters or monochromators for the spectrally selectivetransmission of parts of the light bundles, or polarization selectiveelements for the selection of discrete polarization directions of theexcitation or luminescence light are located between the sensor platformand the one or more detectors.
 41. The optical system according to claim1, wherein the excitation light is launched in pulses with a duration of1 fsec to 10 min.
 42. The optical system according to claim 1, whereinthe emission light from the measurement areas is measured time-resolved.43. The optical system according to claim 1, wherein for referencingpurposes light signals of the group comprising excitation light at thelocation of the light sources or after expansion of the excitation lightor after its multiplexing into individual beams, scattered light at theexcitation wavelength from the location of the one or more discretemeasurement areas, and light of the excitation wavelength out-coupled bythe at least one first diffractive grating structure besides themeasurement areas are measured.
 44. The optical system according toclaim 43, wherein the measurement areas for determination of theemission light and of the reference signal do partly or completelyoverlap.
 45. The optical system according to claim 30, wherein anoptimization of the adjustment for optimum in-coupling of excitationlight by means of an in-coupling first diffractive grating structuretowards measurement areas provided in direction of propagation of thein-coupled light is performed upon maximization of the excitation lightout-coupled by an out-coupling second diffractive grating structure andmeasured by a detector.
 46. The optical system according to claim 45,wherein a rotation of the optical component with several discrete facetsfor beam deflection, around an axis located inside or outside of saidoptical component, is performed for the optimization of the adjustmentof the coupling angle.
 47. The optical system according to claim 1,wherein the optical component with several discrete facets for beamdeflection is connected with a rotary element with axis of rotationinside or outside of said optical component in such a way, that theoffset of the beam on the sensor platform is less than 0.3 mm upon arotation of said optical component around said axis of rotation by lessthan 5°.
 48. The optical system according to claim 1, wherein theoptical system comprises means for translation of the sensor platform inparallel or perpendicular to the grating lines for optimization of thecoupling position.
 49. The optical system according to claim 43, whereinan optimization of the adjustment for optimum in-coupling of excitationlight by means of an in-coupling first diffractive grating structuretowards measurement areas provided in the direction of propagation ofthe in-coupled light is performed upon maximization of one or morereference signals from one or more measurement areas on the sensorplatform.
 50. The optical system according to claim 49, wherein saidreference signal is scattered light of the excitation wavelength. 51.The optical system according to claim 49, wherein said reference signalis luminescence light from measurement areas dedicated for purposes ofreferencing and/or of adjustment.
 52. The optical system according toclaim 1, wherein the irradiation of the excitation light to anddetection of emission light from one or more measurement areas isperformed sequentially for one or more measurement areas.
 53. Theoptical system according to claim 52, wherein the sensor platform ismoved between steps of sequential excitation and detection.
 54. Ananalytical system, for the determination of one or more analytes in atleast one sample on one or more measurement areas on a sensor platformof the optical system according to claim 1 by luminescence detection,whereby the analytical system comprises the optical system according toclaim 1 and further comprises supply means for bringing the one or moresamples into contact with the measurement areas on the sensor platform.55. The analytical system according to claim 54, wherein said analyticalsystem additionally comprises one or more sample compartments, which areat least in the area of the one or more measurement areas or of themeasurement areas combined to segments open towards the sensor platform.56. The analytical system according to claim 55, wherein the samplecompartments have a volume of 0.1 nl-100 μl each.
 57. The analyticalsystem according to claim 55, wherein the sample compartments areclosed, except for inlet and/or outlet openings for the supply or outletof samples, at their side opposite to the first optically transparentlayer, and wherein the supply or the outlet of the samples is performedin a closed flow-through system, wherein, in case of liquid supply toseveral measurement areas or segments with common inlet and outletopenings, these openings are addressed row by row or column by column.58. The analytical system according to claim 55, further comprisingparallel or crossed microchannels wherein the sample is applied by theparallel or crossed micro-channels upon exposure to pressure differencesor electric or electromagnetic potentials.
 59. The analytical systemaccording to claim 55, wherein the sample compartments are provided withopenings at the side facing away from the first optically transparentlayer, for locally addressed supply or removal of the samples or ofother reagents.
 60. The analytical system according to claim 55, whereinthe sample compartments are arranged in an array, comprising the sensorplatform as the base plate and a body combined therewith in such a way,that an array of cavities is generated between the base plate and saidbody, for generation of an array of flow cells fluidically sealedagainst each other, and that at least one outlet of each flow cell leadsto a reservoir fluidically connected with said flow cell and capable toreceive liquid exiting from said flow cell.
 61. The analytical systemaccording to claim 60, wherein the reservoir for receiving liquidexiting from the flow cell is provided as a recess in the exterior wallof the body combined with the base plate.
 62. The analytical systemaccording to claim 54, wherein said analytical system comprises 2-2000sample compartments.
 63. The analytical system according to claim 55,wherein the geometrical arrangement in rows and/or columns of the inletsof the sample compartments does correspond to the geometricalarrangement of the wells of a standard microtiter plate.
 64. Theanalytical system according to claim 60, wherein the arrangement ofsample compartments with the sensor platform as the base plate and thebody combined therewith does correspond to the footprint of a standardmicrotiter plate.
 65. The analytical system according to claim 54,comprising 2 to 8 sample compartments in a column or 2 to 12 samplecompartments in a row, wherein said sample compartments in a column orrow are combined with a carrier (“meta-carrier”) with the dimensions ofstandard microtiter plates in such a way, that the geometricalarrangement in rows and/or columns of the inlets of the flow cells doescorrespond to the geometrical arrangement of the wells of a standardmicrotiter plate.
 66. The analytical system according to claim 60,wherein a removable bottom protection is provided below the sensorplatform as the base plate of an arrangement of sample compartments, andwherein the upper side of the arrangement of sample compartments isclosed with an additional covering top or a cover plate.
 67. Theanalytical system according to claim 66, further comprising means forautomatic or semi-automatic removal of the bottom protection before ameasurement is started.
 68. The analytical system according to claim 55,wherein the at least one first diffractive grating structure of a sensorplatform is provided within each sample compartment.
 69. The analyticalsystem according to claim 55, wherein the sensor platform furthercomprises second diffractive grating structures for the out-coupling ofexcitation light, in addition to first diffractive grating structuresfor the in-coupling of excitation light, in order to out-couple againthe light guided in the first optically transparent layer, after itspassing through the region of the measurement areas in direction ofpropagation of the guided excitation light following an in-couplingfirst diffractive grating structure, and wherein the first diffractivegrating structures are provided within the range of the samplecompartments and said second diffractive grating structures for lightout-coupling are always arranged outside of those sample compartmentswhere the in-coupling is performed.
 70. The analytical system accordingto claim 55, wherein the first diffractive grating structures extendover the range of several or of all sample compartments of the sensorplatform.
 71. The analytical system according to claim 55, wherein5-5000 measurement areas are provided in one sample compartment.
 72. Theanalytical system according to claim 60, further comprising a transportmechanism for an automated transport of an arrangement of samplecompartments, said arrangement comprising a sensor platform as a baseplate and a body combined therewith, from a location of the insertion ofthat arrangement to the location of luminescence excitation anddetection.
 73. The analytical system according to claim 54, wherein saidanalytical system additionally comprises a receiving device (“stacker”)for receiving a plurality of arrangements of sample compartments. 74.The analytical system according to claim 73, wherein the loading of the“stacker” from the position of the insertion of the arrangement ofsample compartments and the transport of said arrangement of samplecompartments from there to the location of luminescence excitation anddetection and then back to the original location is performedautomatically.
 75. The analytical system according to claim 54, whereinsaid analytical system comprises one or more temperature-controllablezones.
 76. The analytical system according to claim 75, wherein thearrangement of sample compartments and/or the excitation light sourcesand/or the one or more opto-electronic detectors and/or the “stacker”can be temperature-controlled separately.
 77. The analytical systemaccording to claim 73, wherein the arrangement of sample compartmentsand/or the excitation light sources and/or the one or moreopto-electronic detectors and/or the “stacker” are operated under ahigher air pressure than ambient pressure.
 78. The analytical systemaccording to claim 54, wherein said analytical system additionallycomprises one or more electronic control components for control of thestatus of one or more optical or electrical or mechanical components,which control components can generate an optical or acoustic orelectronic alarm signal if necessary.
 79. The analytical systemaccording to claim 54, wherein said analytical system additionallycomprises one or more electronic processors, connected to storage mediaand electronic connecting media, a keyboard for data or command input, ascreen and a program code for automated operation.
 80. The analyticalsystem according to claim 54, wherein the operation of said analyticalsystem and/or the measurement are performed automatically usingpre-defined files for initialization.
 81. The analytical systemaccording to claim 54, wherein said analytical system is resetautomatically to a pre-defined initial status and possibly generatedmeasurement data are secured in a file, when an indicated error functionhas occurred.
 82. The analytical system according to claim 54, wherein afile is generated automatically for each measurement, in which file arestored the code of the used sensor platform, the essential measurementparameters and the measurement data.
 83. The analytical system accordingto claim 54, wherein local variations of the excitation light intensityon the sensor platform and/or of the detection sensitivity of theoptical system for light signals from different positions on the sensorplatform are corrected using means which comprise the recording ofimages for correction taken at the excitation wavelength and/or at oneor more luminescence wavelengths, the calculation of theoreticaldistributions of the available excitation light intensity, theoreticalcalculations of the locally resolved efficiency of the optical imagingand detection system.
 84. A method for the determination of one or moreanalytes by luminescence detection, upon using the analytical systemaccording to claim 54, wherein one or more liquid samples to be analyzedfor the one or more analytes are brought into contact with one or moremeasurement areas on the sensor platform, excitation light is directedtowards the measurement areas, thus exciting compounds capable ofluminescence in the sample or on the measurement areas to luminescenceand the emitted luminescence is measured.
 85. The method according toclaim 84, wherein for generation of luminescence at least oneluminescent dye or luminescent nanoparticle is used as a luminescencelabel, which can be excited and emits at a wavelength between 300 nm and1100 nm.
 86. The method according to claim 84 characterized in that itcomprises means to extend the dynamic range for signal recording by atleast a factor of
 3. 87. The method according to claim 86, wherein themeans for extending the dynamic range comprise the application ofdifferently long exposure times, i.e., the duration of the irradiationof the excitation light and the integration time of the detector, whichexposure times can be varied by at least a factor of
 3. 88. The methodaccording to claim 86, wherein the means for extending the dynamic rangecomprise a variation of the excitation light available on the sensorplatform by at least a factor of 3, for example upon using discreteneutral density filters in the excitation beam path, optionally providedas a “continuously varying” filter with a continuous local gradient ofthe transmission, or upon variation of the intensity of the lightsources or upon changing the adjustment of the sensor platform withrespect to the excitation beam path.
 89. The method according to claim84, wherein the at least one luminescence label is bound to the analyteor, in a competitive assay, to an analyte analogue or, in a multi-stepassay, to one of the binding partners of the immobilized biological orbiochemical or synthetic recognition elements or to the biological orbiochemical or synthetic recognition elements.
 90. The method accordingto claim 84, wherein a second or more luminescence labels of similar ordifferent excitation wavelength as the first luminescence label andsimilar or different emission wavelength are used.
 91. The methodaccording to claim 90, wherein charge or optical energy transfer from afirst luminescent dye acting as a donor to a second luminescent dyeacting as an acceptor is used for the detection of the analyte.
 92. Themethod according to claim 84, wherein the one or more luminescencesand/or determinations of light signals at the excitation wavelengths areperformed polarization-selective.
 93. The method according to claim 84,wherein the one or more luminescences are measured at a polarizationthat is different from the one of the excitation light.
 94. The methodaccording to claim 84 for the simultaneous or sequential, quantitativeor qualitative determination of one or more analytes of the groupcomprising antibodies or antigens, receptors or ligands, chelators or“histidin-tag components”, oligonucleotides, DNA or RNA strands, DNA orRNA analogues, enzymes, enzyme cofactors or inhibitors, lectins andcarbohydrates.
 95. The method according to claim 84, wherein the samplesto be examined are naturally occurring body fluids, such as blood,serum, plasma, lymph or urine, or egg yolk or optically turbid liquidsor tissue fluids or surface water or soil or plant extracts or bio- orprocess broths, or are taken from biological tissue fractions or fromcell cultures or cell extracts.
 96. A method comprising performing withthe optical system according to claim 1, at least one or morequantitative or qualitative analyses for the determination of chemical,biochemical or biological analytes in screening methods inpharmaceutical research, combinatorial chemistry, clinical andpre-clinical development, real-time binding studies and thedetermination of kinetic parameters in affinity screening and inresearch, qualitative and quantitative analyte determinations,especially for DNA- and RNA analytics, generation of toxicity studiesand the determination of gene and protein expression profiles, and thedetermination of antibodies, antigens, pathogens or bacteria inpharmaceutical product development and research, human and veterinarydiagnostics, agrochemical product development and research, symptomaticand pre-symptomatic plant diagnostics, patient stratification inpharmaceutical product development and the therapeutic drug selection,the determination of pathogens, nocuous agents and germs, especially ofsalmonella, prions and bacteria, in food and environmental analytics.97. The analytical system according to claim 55, wherein the sensorplatform further comprises second diffractive grating structures for theout-coupling of excitation light, in addition to first diffractivegrating structures for the in-coupling of excitation light, in order toout-couple again the light guided in the first optically transparentlayer, after its passing through the region of the measurement areas indirection of propagation of the guided excitation light following anin-coupling first diffractive grating structure, and wherein firstdiffractive grating structures extend over the range of several or ofall sample compartments.
 98. The analytical system according to claim55, wherein the sensor platform further comprises second diffractivegrating structures for the out-coupling of excitation light, in additionto first diffractive grating structures for the in-coupling ofexcitation light, in order to out-couple again the light guided in thefirst optically transparent layer, after its passing through the regionof the measurement areas in direction of propagation of the guidedexcitation light following an in-coupling first diffractive gratingstructure, and wherein the first diffractive grating structures andadditional the second diffractive grating structures extend over therange of several or of all sample compartments.
 99. A method for thedetermination of one or more analytes by luminescence detection, uponusing the analytical system according to claim 55, wherein one or moreliquid samples to be analyzed for the one or more analytes are broughtinto contact with one or more measurement areas on the sensor platform,excitation light is directed towards the measurement areas, thusexciting compounds capable of luminescence in the sample or on themeasurement areas to luminescence and the emitted luminescence ismeasured.
 100. A method comprising performing with an analytical systemaccording to claim 54 at least one or more quantitative or qualitativeanalyses for the determination of chemical, biochemical or biologicalanalytes in screening methods in pharmaceutical research, combinatorialchemistry, clinical and pre-clinical development, real-time bindingstudies and the determination of kinetic parameters in affinityscreening and in research, qualitative and quantitative analytedeterminations, especially for DNA- and RNA analytics, generation oftoxicity studies and the determination of gene and protein expressionprofiles, and the determination of antibodies, antigens, pathogens orbacteria in pharmaceutical product development and research, human andveterinary diagnostics, agrochemical product development and research,symptomatic and pre-symptomatic plant diagnostics, patientstratification in pharmaceutical product development and the therapeuticdrug selection, the determination of pathogens, nocuous agents andgerms, especially of salmonella, prions and bacteria, in food andenvironmental analytics.
 101. The optical system according to claim 16,wherein a thin metal layer is deposited between the first opticallytransparent layer and the adhesion-promoting layer with immobilizedbiological or biochemical or synthetic recognition elements thereon,wherein the thickness of the metal layer and of the adhesion-promotinglayer is selected in such a way that surface plasmon can be excited atthe excitation and/or luminescence wavelength.
 102. The optical systemaccording to claim 1, wherein the first diffractive grating structure isa relief grating structure.
 103. The optical system according to claim30, wherein the second diffractive grating structure is a relief gratingstructure.